Thermosiphoning

[sam1000]

I have a situation where there is a reservoir of hot water on top of which is a vertical tube closed at the top end. The vertical tube is in communication with the hot fluid at the bottom and is air cooled externally. I am trying to determine the natural circulation flow rate inside the tube, internal fluid temperature profile, and the internal heat transfer coefficient.

I have found plenty of papers and information for thermosiphoning where the hot and cold fluid streams are physically separated but very little with respect to the flow situation I am trying to model. If anyone has experience in this area or could point me to some information, it would be greatly appreciated.

 

[btrueblood]

What you have described sounds quite familiar. Took me awhile to recall a commonplace example, but here it is: a "lava lamp". I would expect your setup to have the same kind of chaotic flow conditions, characterised by rising plumes of hot (low density) fluid "battling" against falling plumes of cooled (denser) fluid.